Astell&Kern PEE51 USB-C DAC

Astell&Kern PEE51 USB-C DAC – no 3.5mm port – no problem (review)


The Astell&Kern PEE51 USB-C DAC adds a 3.5mm, 3-pole socket to any UBS-C equipped Windows or macOS computer or Android smartphone. You can listen to music from MP3s to as intended at up to 32bit/384kHz.

Or put another way, it vastly improves the audio quality of any smartphone or laptop. Now that is not an issue with lossy MP3, AAC, or MP4 video as most people listen via entry-level cabled or BT buds.

The Astell&Kern PEE51 USB-C DAC is not just another low-cost USB-C to 3.5mm audio adaptor that is thrown in with your smartphone. It enables support for high-quality, high-resolution audio to provide the full audio playback experience via cabled headphones.

Astell&Kern PEE51 USB-C DAC to 3.5mm

  • Global Product Website here
  • Manual and Windows 10 downloads here
  • Astell&Kern AU website here
  • Price: A$169 free delivery
  • From: Addicted to Audio and select audio retailers (click here for a list)
  • Warranty: 12 months (presume ACL compliant – take care if buying internationally)
  • Astell&Kern is a South Korean consumer electronics company (Est 2013) that focuses on Mastering Quality Sound or MQS (24-bit/192kHz) – natural and original sound without distortion.

What is under the hood?

It is a small metal stereo USB-C DAC/AMP with a 3.5mm output. Inside is the Cirrus Logic CS43198 Master HIFI chipset that supports up to DSD256 content and PCM 32bit/384kHz. It is line powered from the USB-C (hence not for iOS lightning connectors). The dual DACs feed an independent stereo analogue amp with sufficient power to drive high-impedance headphones with a 2Vrms output level.  

Note that you may need a high-res audio player app for hi-res and DSD music. A free one is Hysolid (Windows) that will get you started. There are a few more free and paid players here

Astell&Kern PEE51 USB-C DAC

The cable is a work of art

It has a 4-core cable to reinforced to withstand up to 200N of tensile force using aramid fibre. It uses silver-plated copper wire (0.3μm, usually 0.1~0.15µm) and wraps that in a spiral form around a centre Technora Aramid fibre to block external noise. A separate shielding blocks distortion and digital and analogue noise signals from the playback device. The zinc alloy body dissipates heat – it can get toasty.

Astell&Kern PEE51 USB-C DAC

Windows/Mac/Android – not iOS

Windows automatically installs a generic driver. Download an Astell&Kern DAC driver, especially if you plan to play DSD content. It supports all bit rates. macOS finds the device and shows it supports up to 32-bits/384kHz. Android finds the DAC but take care because the USB-C connector won’t fit many protective cases.

How does it sound?

Alas, our resident audiophile Thomas Bartlett has moved on, so you are stuck with me – an amateurphile. We tested with a pair of Sennheiser Momentum 3 (10/10 disabled ANC and BT using the 3.5mm cable). We also used a pair of pro-grade, Sennheiser HD560S (9.6/10) 120Ω 6Hz-38000kHz.

 In comparison to Bluetooth music, listening via the Asetll&Kern PEE51 DAC was an experience I won’t forget. The wired Sennheiser needed about 25/100 volume before it was unreasonably loud. The Momentum 3 needed a little more, but you can supplement that with its onboard amp.

For a full audiophile-class review, click here.

Astell&Kern PEE51 USB-C DAC

Astell&Kern PEE51 USB-C DAC Amplifier cable PEE51 specs

  • Windows, macOS, Android – NOT iOS or ARM64 hardware
  • Body: Zinc Alloy Titan colour x 25g
  • DAC and AMP: 2 x Cirrus Logic CS43198
  • Input: USB Type-C Class 2.0 Audio (Android devices must have OTG enabled)
  • Output: 3.5mm 3-pole headphone
  • Frequency response: 20 Hz~20 kHz – +/- 0.03
  • Sample Rate:
    • PCM: Support up to 32bit/384kHz
    • DSD Native: DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo / DSD256(1bit 11.2MHz), Stereo
  • Signal-to-Noise Ratio: 118dB @ 1kHz, Unbalanced
  • THD+N: 0.0004% @ 1kHz, Unbalanced
  • IMD SMPTE: 0.0003% 800Hz 10kHz (4:1) Unbalanced
  • Output impedance: 2ohm
  • Output power or voltage: 2Vrms (condition no load)

GadgetGuy’s take

For the sake of science, I also tested a Google Pixel USB-C to 3.5mm adapter. The audio quality difference was palpable. Where the Astell&Kern PEE51 USB-C DAC could reproduce everything from very low bass to very high treble, the adapter was bland by comparison. It is probably poor form to compare a $16 adapter to a $166 DAC, but hey.

For those that want analogue audiophile class output from a digital computer or smartphone – you can’t go past this.

You can read other GadgetGuy Astell&Kern news and reviews here.

Astell&Kern PEE51 USB-C DAC
For those that want analogue audiophile class output from a digital computer or smartphone – you can’t go past this.
Value for money
Ease of use
Capable of audiophile-grade playback with the right content, player and drivers
Seems to reduce high treble harshness without compressing sound
Perfect from low bass to high treble
Does not support 4-pole 3.5mm – disables the mic
Gets a little toasty - nice in winter
No digital bit/frequency readout